A new superstructure of the mineral camerolaite, Cu6Al3(OH)18(H2O)2[Sb(OH)6](SO4), has been refined in space groupP\bar 1 with unit-cell parametersaP= 7.7660 (16),bP= 8.759 (4),cP= 11.306 (2) Å, αP= 108.67 (4), βP= 83.41 (3), γP= 126.64 (2)°,V= 581.6 (3) Å3andZ= 1, withR1= 0.0951 (all data). This is the first refined example of a cyanotrichite-group mineral in which long-range order of interlayer anions produces a superstructure alongb, although diffuse scattering has previously been reported that corresponds to short-range order. Though the structure shares with other members of the cyanotrichite group a structural unit in which ribbons of edge-sharing Cu and Al octahedra form layers || (001), the superstructure arises from regular alternation of [SO4] and [Sb(OH)6] polyhedra along rods that lie between the layers, and phase coupling between rods that maximizes the distance between [SO4] groups of adjacent rods alongaandcdirections. This arrangement suggests an alternative nearly orthogonal choice of unit cell inF\bar 1 with parametersaF= 12.473 (26),bF= 8.759 (4),cF= 21.476 (7) Å, αF= 85.94 (4), βF= 95.91 (5), γF= 92.34 (9)°, which is recommended for comparing this structural variety of camerolaite with other members of the group.
Association Between Phase Coupling of Respiratory Sinus Arrhythmia and Slow Wave Brain Activity During Sleep
